1. Field Of The Invention
The invention herein pertains to devices to grip and maintain ropes in a desired position and particularly pertains to locking ropes as are used in suspension systems for curtains, scenery, lights, and other equipment in auditoriums, coliseums, exhibit halls, theaters, and other arenas.
2. Description Of The Prior Art And Objectives Of The Invention
Various types of riggings and systems have been used in the past to raise, lower, and suspend scenery, curtains, lighting equipment, audio devices, cameras, and other equipment for theatrical productions, displays, exhibitions, and other events. A counterweight rigging is popular for the theater industry and is comprised of certain components including a head block, a counterweight arbor, a floor block, a rope lock, loft blocks, a pipe batten, lift lines (aircraft cables), and a rope handline.
A counterweight rigging is used to lift objects overhead on a stage or other location. An item that is to be lifted is attached to the pipe batten on stage and an equal amount of counterweight is added to the counterweight arbor. The counterweight arbor, in this balanced condition, is able to be moved with a minimum of effort by pulling on the handline. The rope lock is an essential component in that it is used to hold (lock) the handline when the counterweight set is not in use.
Should an item be attached to the pipe batten and no additional weight added to the counterweight arbor, the rigging would be out of balance. When the rigging is used in this condition, the operator, after releasing the rope lock, may not be able to control the ascent or descent of the pipe batten. When the rope lock is released, the out-of-balance rigging will start to travel without the assistance of the operator and the operator may not be able to stop the rigging from "running away", continuing its descent until the overbalanced side of the counterweight rigging strikes a stop or other obstacle in its path.
As a solution to the problems often encountered with such counterweight rigged systems, a present invention was conceived and one of its objectives is to provide a rope locking device which will prevent an out-of-balance counterweight rigging from movement, even if the rope handle has been moved to a release position by the operator.
It is another objective of the new invention to provide a rope locking device which includes a manual release handle to allow the rope of a properly balanced counterweight rigging to pass freely through the locking device when desired.
It is still another objective of the present invention to provide a rope locking device which is rigidly mounted to a floor, wall, or other structure.
It is yet another objective of the present invention to provide a rope locking device which includes a pair of resiliently mounted, opposing jaws having lateral grooved surfaces which tenaciously grip the rope.
It is also an objective of the present invention to provide a rope locking device having a convenient means to adjust the tension of the jaws on the rope as needed.